Simulating micro-proppant flow through microfractures

Abstract

A conductivity cell for simulating micro-proppant flowing through microstructures includes a core wafer holder defining a fluid inlet and a fluid outlet, with a core wafer chamber connecting the fluid inlet in fluid communication with the fluid outlet. A core wafer is installed within the core wafer chamber of the core wafer holder. A pressure piston is biased against the core wafer within the core wafer chamber. A pre-determined channel gap is defined on the core wafer for passage of the fluid through the cell.

What is claimed is: 
     
       1. A method of simulating micro-proppant flowing through microstructures comprising:
 injecting a fluid including micro-proppant through a conductivity cell, wherein the conductivity cell includes a core wafer wherein a plurality of pre-determined channel gaps are defined on the core wafer for passage of the fluid through the conductivity cell, wherein the channel gaps are defined between a plurality of leaflets or sheets, the leaflets or sheets being arranged lengthwise along the core wafer in at least four rows with gaps arranged between the leaflets or sheets in each row such that sub-channels are defined running widthwise across the core wafer, and wherein the plurality of leaflets or sheets are bounded by the core wafer; and 
 measuring pressure drop across flow through the conductivity cell. 
 
     
     
       2. A method as recited in  claim 1 , wherein the channel gaps have a width simulating a natural microfracture at 5 to 1,000 microns width. 
     
     
       3. A method as recited in  claim 1 , wherein the leaflets or sheets are mounted to the core wafer. 
     
     
       4. A method as recited in  claim 3 , wherein the leaflets or sheets are plastic. 
     
     
       5. A method as recited in  claim 3 , wherein the channel gaps are defined by folding, stacking, precision cutting, or laser cutting a number of leaflets or sheets. 
     
     
       6. A method as recited in  claim 1 , wherein the core wafer includes at least one of metal, a sandstone, or a shale material. 
     
     
       7. A method as recited in  claim 1 , wherein at least one of the core wafer and a core holder holding the core wafer is made of a transparent material including poly(methylmethacrylate) (PMMA). 
     
     
       8. A method as recited in  claim 1 , further comprising controlling at least one of closure pressure on the channel gaps or temperature within the channel gaps to simulate natural conditions in a formation. 
     
     
       9. A method as recited in  claim 1 , wherein the plurality of leaflets or sheets include rectangular leaflets or sheets. 
     
     
       10. A conductivity cell for simulating micro-proppant flowing through microstructures comprising:
 a core wafer holder defining a fluid inlet and a fluid outlet, with a core wafer chamber connecting the fluid inlet in fluid communication with the fluid outlet; 
 a core wafer installed within the core wafer chamber of the core wafer holder; and 
 a pressure piston biased against the core wafer within the core wafer chamber, wherein a plurality of pre-determined channel gaps are defined on the core wafer for passage of the fluid through the core wafer chamber, wherein the channel gaps are defined between a plurality of leaflets or sheets, the leaflets or sheets being arranged lengthwise along the core wafer in at least four rows with gaps arranged between the leaflets or sheets in each row such that sub-channels are defined running widthwise across the core wafer, and wherein the plurality of leaflets or sheets are bounded by the core wafer. 
 
     
     
       11. A conductivity cell as recited in  claim 10 , further comprising at least one of a pressure control loop operatively connected to control the pressure piston to provide a predetermined pressure to the channel gaps; or
 a temperature control loop operatively connected to control temperature within the channel gaps to provide a predetermined temperature in the channel gaps. 
 
     
     
       12. A conductivity cell as recited in  claim 11 , wherein the channel gaps have a width simulating a natural microfracture at 5 to 1,000 microns width. 
     
     
       13. A conductivity cell as recited in  claim 11 , wherein the leaflets or sheets are mounted to the core wafer. 
     
     
       14. A conductivity cell as recited in  claim 13 , wherein the leaflets or sheets are metallic leaflets of at least one of aluminum, stainless steel, copper, silver, nickel, ceramic, or composite elastomer. 
     
     
       15. A conductivity cell as recited in  claim 13 , wherein the leaflets or sheets are plastic. 
     
     
       16. A conductivity cell as recited in  claim 13 , wherein the channel gaps are defined by folding, stacking, precision cutting, or laser cutting a number of leaflets or sheets. 
     
     
       17. A conductivity cell as recited in  claim 11 , wherein the channel gaps are configured to simulate a complex fracture network including multiple sub-channels. 
     
     
       18. A conductivity cell as recited in  claim 11 , wherein the core wafer includes at least one of a metal, a sandstone or a shale material. 
     
     
       19. A conductivity cell as recited in  claim 11 , wherein at least one of the core wafer or the core wafer holder is made of a transparent material including poly(methyl methacrylate) (PMMA). 
     
     
       20. A conductivity cell as recited in  claim 11 , wherein the plurality of leaflets or sheets include rectangular leaflets or sheets.